<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <div class="box"></div>
</body>

</html>

<style>
    .box {
        width: 0;
        height: 0;
        border-radius: 50%;
        border: 60px solid #f00;
        border-right: 60px solid transparent;
    }
</style>